| Age | Commit message (Collapse) | Author |
|---|
|
The jbd2 layer enables NOFS mode using memalloc_nofs_{save,restore}()
while a handle is active. We need to do the same in nojournal mode so
that it is safe to remove GFP_NOFS flags while a jbd2 handle is
active.
This will require that we actually allocate a real handle, but with an
h_invalid flag set, so there is a place to put the saved memalloc
context.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
|
|
- don't use "/**" for non-kernel-doc comments
- use the struct keyword when describing structs
- delete one Excess struct member
to prevent the following warnings:
Warning: ./fs/ecryptfs/ecryptfs_kernel.h:14 cannot understand function
prototype: 'ECRYPTFS_KERNEL_H'
Warning: ./fs/ecryptfs/ecryptfs_kernel.h:207 This comment starts with
'/**', but isn't a kernel-doc comment.
* This is the primary struct associated with each encrypted file.
Warning: ./fs/ecryptfs/ecryptfs_kernel.h:275 cannot understand function
prototype: 'struct ecryptfs_global_auth_tok'
Warning: fs/ecryptfs/ecryptfs_kernel.h:283 Excess struct member
'global_auth_tok' description in 'ecryptfs_global_auth_tok'
Warning: ./fs/ecryptfs/ecryptfs_kernel.h:298 cannot understand function
prototype: 'struct ecryptfs_key_tfm'
Warning: ./fs/ecryptfs/ecryptfs_kernel.h:309 This comment starts with
'/**', but isn't a kernel-doc comment.
* This struct is to enable a mount-wide passphrase/salt combo. This
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tyler Hicks <code@tyhicks.com>
|
|
FALLOC_FL_WRITE_ZEROES requires that all blocks in the requested range
end up as written extents with zeroed content. For unaligned edges that
were partial-zeroed in dirty unwritten or delalloc state, the buffer
is left dirty while the underlying extent may not yet be converted to
written. As a result, a subsequent SYNC write to this range would still
trigger metadata changes, which violates the semantics of WRITE_ZEROES.
Fix this by calling filemap_write_and_wait_range() for partial-zeroed
edges to flush out the zeroed data and ensure the extent conversion
is complete.
Fixes: f4265b8d32c4 ("ext4: add FALLOC_FL_WRITE_ZEROES support")
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260714080044.4038124-9-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
FALLOC_FL_WRITE_ZEROES requires that all blocks in the requested range
end up as written extents with zeroed content. For unaligned edges that
were already allocated, ext4_zero_partial_blocks() zeros them directly.
However, for unaligned edges whose underlying extent is a clean
unwritten extent or a hole, the extent type remains unwritten after
partial zeroing, which does not align with the semantics of
WRITE_ZEROES.
Therefore, when ext4_zero_partial_blocks() skips partial zeroing, it
indicates that the corresponding edges are clean unwritten extents or
holes. In this case, we need to expand the aligned allocation range
outward to cover such edges, so that ext4_alloc_file_blocks() can
correctly allocate blocks for the unaligned range. Edges that were
partial-zeroed (i.e., written or dirty) are left untouched.
Fixes: f4265b8d32c4 ("ext4: add FALLOC_FL_WRITE_ZEROES support")
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260714080044.4038124-8-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Replace the single bool did_zero output of ext4_zero_partial_blocks()
with a bitmask that records which edge (start, end, or both in the
single-block case) was actually partial-zeroed. This allows callers to
distinguish which edges have been zeroed, preparing for unaligned
FALLOC_FL_WRITE_ZEROES handling in later patches.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260714080044.4038124-7-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
ext4_load_tail_bh() returns NULL for both holes and clean unwritten
buffers, but the conditions that lead to this are not obvious from the
code alone. Document this behavior to clarify the return value, so that
readers do not mistakenly assume that only holes result in a NULL
return.
Also update the inline comment following the ext4_get_block() call to
reflect this, and note that a lookup-only get_block (without
EXT4_GET_BLOCKS_CREATE) never sets BH_Mapped for clean unwritten
extents, which is why a clean unwritten bh falls through to the
"nothing to do" path.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260714080044.4038124-6-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
In ext4_zero_range(), move the ext4_zero_partial_blocks() call, which
handles unaligned edges, into the same branch where the unaligned range
is preallocated, immediately after ext4_alloc_file_blocks(). This is
safe because there is no dependency between partial block handling and
the subsequent full block handling.
This change will be used by later patches that handle unaligned
FALLOC_FL_WRITE_ZEROES operations, which will need to check the partial
zeroed result.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260714080044.4038124-5-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
ext4_load_tail_bh() ignores the return value of ext4_get_block(), so an
I/O or allocation failure is silently discarded. buffer_mapped(bh) stays
false and the function returns NULL, which callers such as
ext4_block_do_zero_range() treat as "nothing to do" and return success.
This can mask real failures during zero-range, truncate, or punch-hole
operations, potentially exposing stale data if the block was not
actually a hole and needed zeroing. So propagate the error to the
callers.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260714080044.4038124-4-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
ext4_block_zero_eof() is called from ext4_write_checks() on every
append write beyond EOF. For inline data files, ext4_get_block()
returns -ERANGE when ext4_load_tail_bh() looks up the tail block.
However, this error is currently ignored because the return value
of ext4_get_block() in ext4_load_tail_bh() is discarded.
Before we fix ext4_load_tail_bh() to properly propagate the error,
skip the zeroing for inline data inodes to avoid unnecessary
failures or confusion.
Fixes: 3f60efd65412d ("ext4: zero post-EOF partial block before appending write")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260714080044.4038124-3-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
ext4_load_tail_bh() returns a locked folio that callers immediately
mutate through folio_zero_range() and mark_buffer_dirty(). Use
FGP_WRITEBEGIN so that, on backing devices that require stable writes,
__filemap_get_folio() waits for writeback to finish before returning
the folio; on regular devices the wait is a no-op.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260714080044.4038124-2-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
The jbd2 shrinker currently accounts only checkpoint buffers that it
successfully releases against nr_to_scan. Busy buffers therefore do not
consume the scan budget.
If a checkpoint transaction contains mostly busy buffers, the shrinker
can scan its entire checkpoint list while holding journal->j_list_lock.
Large checkpoint lists can result in excessive lock hold times and leave
other CPUs spinning on j_list_lock, causing soft lockups or RCU stalls.
Pass nr_to_scan into journal_shrink_one_cp_list() and decrement it for
every buffer examined, including busy buffers. Pass NULL from checkpoint
cleanup paths so their existing full-list behavior is preserved.
This restores the scan-budget semantics that existed before
journal_shrink_one_cp_list() was changed to always scan a complete
checkpoint list.
Fixes: b98dba273a0e ("jbd2: remove journal_clean_one_cp_list()")
Cc: stable@vger.kernel.org
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260713102229.1598812-3-max.kellermann@ionos.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
journal_shrink_one_cp_list() skips busy checkpoint buffers when called
with JBD2_SHRINK_BUSY_SKIP. The continue statement on this path also
skips the need_resched() check at the end of the loop body.
Consequently, when a checkpoint list contains mostly busy buffers, the
shrinker can walk the entire list while holding journal->j_list_lock,
even when a reschedule has been requested. Large checkpoint lists under
memory pressure can therefore cause long lock hold times and leave other
CPUs spinning on j_list_lock, resulting in soft lockups or RCU stalls.
Route the busy-buffer path through the need_resched() check so that the
shrinker can release j_list_lock and reschedule promptly, restoring
parity with the clean-buffer path, which already checks need_resched().
This does not change which checkpoint buffers are eligible for removal.
Fixes: b98dba273a0e ("jbd2: remove journal_clean_one_cp_list()")
Cc: stable@vger.kernel.org
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260713102229.1598812-2-max.kellermann@ionos.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Remove the custom PLURAL() macro and use str_plural() from
string_choices.h instead.
Reviewed-by: Baokun Li <libaokun@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joshua Crofts <joshua.crofts1@gmail.com>
Link: https://patch.msgid.link/20260713-remove-plural-macro-v2-1-424e1536ac10@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Now that ext4_put_ea_inode() handles deferred iput safely for all cases
(using iput_if_not_last + embedded llist_node), the ea_inode_array
mechanism for batching deferred iputs is redundant.
Remove:
- ext4_expand_inode_array() and ext4_xattr_inode_array_free()
- struct ext4_xattr_inode_array and EIA_INCR/EIA_MASK defines
- ea_inode_array parameter from ext4_xattr_inode_dec_ref_all(),
ext4_xattr_release_block(), and ext4_xattr_delete_inode()
- ea_inode_array variable from ext4_evict_inode()
Instead, ext4_xattr_inode_dec_ref_all() now calls ext4_put_ea_inode()
directly after processing each EA inode. This simplifies the code
by eliminating multi-layer parameter threading and removes the need
for callers to manage array lifetime.
Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: syzbot@syzkaller.appspotmail.com
Link: https://patch.msgid.link/20260710030851.2791589-5-yun.zhou@windriver.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Convert all iput() calls on EA inodes in xattr code paths to use
ext4_put_ea_inode(). This establishes a uniform rule: every EA inode
reference release in ext4 xattr code goes through ext4_put_ea_inode(),
eliminating the need to analyze each call site individually for lock
safety.
Converted sites:
- ext4_xattr_inode_get() read path
- ext4_xattr_inode_inc_ref_all() main loop and cleanup path
- ext4_xattr_inode_dec_ref_all() error paths
- ext4_xattr_inode_create() error path
- ext4_xattr_inode_cache_find() mismatch path
- ext4_xattr_inode_lookup_create() out_err
- ext4_xattr_set_entry() old_ea_inode
- ext4_xattr_block_set() new block path, cleanup, and tmp_inode
- ext4_xattr_ibody_set() error and success paths
- ext4_xattr_delete_inode() quota loop
For most of these, iput_if_not_last() will succeed (the EA inode has
other references) making the overhead a single atomic operation.
Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: syzbot@syzkaller.appspotmail.com
Link: https://patch.msgid.link/20260710030851.2791589-4-yun.zhou@windriver.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Calling iput() on EA inodes while holding xattr_sem or a jbd2 handle
can trigger write_inode_now() -> ext4_writepages() -> s_writepages_rwsem,
creating a lock ordering issue during mount (!SB_ACTIVE).
Add ext4_put_ea_inode() which uses iput_if_not_last() as a fast path.
If this is not the last reference, it is dropped immediately. If this
is the last reference, the inode is linked onto a per-sb lock-free llist
via i_ea_iput_node (embedded in ext4_inode_info, sharing space with the
unused xattr_sem of EA inodes via a union) and a delayed worker
(1 jiffie) performs the final iput() in a clean context. This avoids
per-iput memory allocation.
Flush points ensure all pending EA inode evictions complete before
dependent resources become unavailable:
- ext4_put_super / failed_mount9: before quota shutdown
- failed_mount_wq: before freeing xattr caches
- failed_mount3a: before freeing shrinker (journal replay case)
- ext4_sync_fs: before remount-ro, freeze, or sync completes
Initialization is placed before journal loading since fast commit
replay may trigger evictions that call ext4_put_ea_inode().
Also moves init_rwsem(xattr_sem) from init_once to ext4_alloc_inode to
handle slab object reuse after the union field has been overwritten.
Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260710030851.2791589-3-yun.zhou@windriver.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
For casefolded encrypted directories ext4 stores an 8-byte hash trailer
after the name (EXT4_DIRENT_HASHES()), at an offset derived from
de->name_len. On the sb_no_casefold_compat_fallback() path ext4_match()
reads that trailer, but ext4_search_dir()'s by-hand pre-check only tests
de->name + de->name_len <= dlimit, which proves the name fits, not the
rounded trailer. A crafted entry whose name ends at the block boundary
passes the check while EXT4_DIRENT_HASHES(de) lands past the block end,
so ext4_match() reads out of bounds on an ordinary lookup. KASAN reports
it as a use-after-free when the page after the directory block holds a
freed object:
BUG: KASAN: use-after-free in ext4_match (fs/ext4/namei.c:1435)
Read of size 4 at addr ffff888010458000 by task exploit
Call Trace:
ext4_match (fs/ext4/namei.c:1435)
ext4_search_dir (fs/ext4/namei.c:1470)
__ext4_find_entry (fs/ext4/namei.c:1268 fs/ext4/namei.c:1632)
ext4_lookup (fs/ext4/namei.c:1703 fs/ext4/namei.c:1769)
...
filename_lookup (fs/namei.c:2842)
vfs_statx (fs/stat.c:353)
__do_sys_newfstatat (fs/stat.c:538)
do_syscall_64 (arch/x86/entry/syscall_64.c:94)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
Require, for hash-in-dirent directories, that the whole entry including
the rounded trailer fits before calling ext4_match(). This is the same
bound ext4_check_dir_entry() already enforces via ext4_dir_rec_len(), so
no well-formed entry is rejected. The other caller, ext4_find_dest_de(),
runs ext4_check_dir_entry() first and is unaffected.
Fixes: 471fbbea7ff7 ("ext4: handle casefolding with encryption")
Reported-by: Weiming Shi <bestswngs@gmail.com>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260709184101.441348-1-xmei5@asu.edu
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
ext4_init_orphan_info() reads orphan file blocks with ext4_bread()
and stores the returned buffer_head in oi->of_binfo[i].ob_bh.
If ext4_bread() succeeds but the orphan block magic or checksum
validation fails, the function jumps to out_free. However, the old
out_free loop starts releasing buffers from i - 1, so the current
buffer_head at index i is skipped.
This leaks the buffer_head reference obtained by ext4_bread() on the
bad magic and bad checksum error paths.
Fix this by tracking the number of successfully read buffer_heads and
releasing exactly those buffer_heads on the error path.
Fixes: 02f310fcf47f ("ext4: Speedup ext4 orphan inode handling")
Signed-off-by: Guanghui Yang <3497809730@qq.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/tencent_B38798612A159E21450ECF959016371B0807@qq.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
When ext4_xattr_make_inode_space() returns -ENOSPC,
ext4_expand_extra_isize_ea() can retry the expansion with
s_min_extra_isize. If that retry succeeds by finding enough ibody free
space, control jumps directly to the shift label.
The previous -ENOSPC is still stored in error in that path, so the
function can update i_extra_isize but still return -ENOSPC to the
caller. Clear error before retrying so a successful fallback expansion
returns success.
Reproduced with an ext4 image using 1 KiB blocks, project quota support,
256-byte inodes, and min_extra_isize/want_extra_isize set to 32.
FS_IOC_FSSETXATTR failures dropped from 802 to 86 after the fix.
Fixes: 69f3a3039b0d ("ext4: introduce ITAIL helper")
Cc: stable@vger.kernel.org
Signed-off-by: Guanghui Yang <3497809730@qq.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/tencent_192F8A699EFD21126E02101131C9546F3C08@qq.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
ext4_fc_replay() stops replaying fast commit tags only when a tag
handler returns a negative error. However, ext4_fc_replay_add_range()
and ext4_fc_replay_del_range() currently return 0 from their common
exit paths even after internal failures.
This hides errors from ext4_fc_record_modified_inode(),
ext4_map_blocks(), ext4_find_extent(), ext4_ext_insert_extent(),
ext4_ext_replay_update_ex(), and ext4_ext_remove_space(). As a result,
a failed ADD_RANGE or DEL_RANGE replay can be treated as successful and
the replay code may continue with subsequent fast commit tags.
This is particularly problematic for DEL_RANGE because it may already
have marked blocks as free before ext4_ext_remove_space() fails. If the
error is swallowed, replay may continue from a partially applied range
operation.
Return the saved error from the common exit paths and make the
ERR_PTR() cases in ADD_RANGE store PTR_ERR() before jumping to out.
Fixes: 8016e29f4362 ("ext4: fast commit recovery path")
Cc: stable@vger.kernel.org
Signed-off-by: Guanghui Yang <3497809730@qq.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/tencent_E3622146846A84C75C31C7D32AC4D5AD0605@qq.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Since at least as far back as commit 0818bf27c05b ("resizable
namespace.c hashes"), we call alloc_large_system_hash() in
mnt_init() which already panics if the table is NULL.
Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Link: https://patch.msgid.link/20260720112331.1096530-1-hamzamahfooz@linux.microsoft.com
Reviewed-by: Jori Koolstra <jkoolstra@xs4all.nl>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
A corrupted directory can trigger the following KASAN report when
ext4_readdir() resumes from an invalid position:
BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x5ef/0x820
Read of size 2 at addr ffff88810a646000 by task repro_linear/509
Call Trace:
<TASK>
dump_stack_lvl+0x53/0x70
print_report+0xd0/0x630
kasan_report+0xce/0x100
__ext4_check_dir_entry+0x5ef/0x820
ext4_readdir+0xcde/0x2b70
iterate_dir+0x1a1/0x520
__x64_sys_getdents64+0x12b/0x220
do_syscall_64+0xf9/0x540
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
KASAN reports use-after-free because the out-of-bounds access lands in an
adjacent freed page. The directory buffer itself is still referenced.
ext4_dir_llseek() invalidates the directory cookie so that ext4_readdir()
rescans directory entries from the start of the block. The rescan checks
only the lower bound of rec_len before advancing. A corrupted rec_len can
therefore place the offset where the block has insufficient space for a
complete directory entry. The rescan itself may dereference that truncated
entry, or the main loop may pass it to __ext4_check_dir_entry(). The latter
reads de->rec_len before validating the range. For example:
block offset 0 4092 4096
|---- de1.rec_len = 4092 -----|----|
de2.inode
| de2.rec_len
^ OOB, reported as UAF
de2 starts at offset 4092 in this 4 KiB block. Its four-byte inode fits in
the block, but its rec_len starts at offset 4096 and crosses the boundary.
The minimum safe length is inode-dependent. Encrypted and casefolded
directory entries need eight additional hash bytes, while a valid metadata
checksum tail is only 12 bytes.
Cache the metadata checksum feature state and derive the minimum directory
entry length from the on-disk format. Use it to bound both the rescan and
the offset passed to the main loop. Report an offset in a truncated block
tail and skip the remainder of the block, while continuing to accept an
offset exactly at the block boundary.
Reported-by: syzbot+5322c5c260eb44d209ed@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=5322c5c260eb44d209ed
Fixes: ac27a0ec112a ("[PATCH] ext4: initial copy of files from ext3")
Signed-off-by: Yao Kai <yaokai34@huawei.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20260706041313.708346-1-yaokai34@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
After implementing bitwise flags for tracking the inline data write
state in the address space fsdata parameter, the CONVERT_INLINE_DATA
state flag is left unused and can be removed.
Perform this clean-up by:
1) Deleting the CONVERT_INLINE_DATA definition from ext4.h.
2) Removing the void **fsdata argument from both the forward
declaration and the definition of the internal helper
ext4_da_convert_inline_data_to_extent().
3) Removing the void **fsdata argument from the declaration and
definition of ext4_generic_write_inline_data() and updating
the caller ext4_try_to_write_inline_data() and the internal
re-alloc retry logic accordingly.
4) Updating ext4_da_write_begin() to call
ext4_generic_write_inline_data() without the fsdata parameter.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Aditya Prakash Srivastava <aditya.ansh182@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260703045414.1768-2-aditya.ansh182@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Instead of checking the live inode state (ext4_has_inline_data(inode)
and ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) in the
write_end handlers, use the fsdata parameter of the address space
operations to explicitly pass down the state in which write_begin
prepared the write.
A concurrent thread (such as ext4_page_mkwrite()) can convert the
inline data to an extent between write_begin and write_end. If this
happens, the write_end handlers would previously miss the inline
write_end path and fall through to extent-based write_end logic.
However, since block buffers were never allocated in write_begin,
this resulted in NULL pointer dereferences or data loss because
folio_buffers(folio) was NULL.
Define EXT4_WRITE_DATA_INLINE (4) as a bit flag (Bit 2), treating
fsdata as bitwise flags rather than mutually exclusive enums to keep
states of the write path independent. Communicate this state via
fsdata:
1) ext4_write_begin() and ext4_da_write_begin() set the
EXT4_WRITE_DATA_INLINE bit in *fsdata via bitwise OR when an inline
write is successfully prepared.
2) On entry, ext4_write_begin() clears the EXT4_WRITE_DATA_INLINE bit
to safely handle VFS retries (where generic_perform_write() bypasses
the fsdata initialization on its retry jump).
3) The write_end handlers perform a bitwise AND to check if the
EXT4_WRITE_DATA_INLINE bit is set and invoke the inline write_end
helper accordingly.
Furthermore, during a buffered write, ext4_write_inline_data_end()
acquires the xattr lock after preparing the write. If a concurrent
page fault (ext4_page_mkwrite()) converts the inline data to an extent
after the write_end handlers check the state but before
ext4_write_inline_data_end() acquires the xattr write lock, the
subsequent check will trigger a kernel panic via
BUG_ON(!ext4_has_inline_data(inode)).
To keep git history working and bisectability clean, replace the
BUG_ON check in ext4_write_inline_data_end() with a graceful error-
handling retry path in this same commit. If the inline data is cleared
after locking the xattr, we safely release all resources (releasing
iloc.bh, unlocking/putting the folio, stopping the active journal
transaction handle) and return 0 (VFS retry) to let the generic write
path retry the operation safely.
Reported-by: syzbot+0c89d865531d053abb2d@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0c89d865531d053abb2d
Fixes: 3fdcfb668fd7 ("ext4: add journalled write support for inline data")
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Aditya Prakash Srivastava <aditya.ansh182@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260703045414.1768-1-aditya.ansh182@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
When a DAX write starts before EOF but extends past i_disksize,
ext4_write_checks() skips the IOCB_NOWAIT check because
iocb->ki_pos <= old_size. However, ext4_dax_write_iter() later calls
ext4_journal_start() to prepare for inode extension, which can sleep
waiting for journal space or transaction commit.
This violates NOWAIT semantics and can stall asynchronous I/O frameworks
like io_uring that rely on non-blocking behavior.
Fix this by checking IOCB_NOWAIT before calling ext4_journal_start()
in the extending write path. If NOWAIT is set and extension is needed,
return -EAGAIN so the caller can retry in blocking context.
Example scenario:
- File: i_size = 1000, i_disksize = 1000
- DAX NOWAIT write: offset = 500, count = 2000
- ext4_write_checks(): ki_pos (500) <= old_size (1000), skip NOWAIT check
- ext4_dax_write_iter(): offset + count (2500) > i_disksize (1000)
- ext4_journal_start() → may sleep → violates NOWAIT
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260618125735.4156639-1-libaokun@linux.alibaba.com?part=5
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20260629113827.4074335-7-libaokun@linux.alibaba.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
file_modified() passes flags=0 which drops IOCB_NOWAIT, causing
file_update_time() to sleep in ext4_journal_start() via
ext4_dirty_inode() even in non-blocking contexts.
kiocb_modified(iocb) propagates iocb->ki_flags so that
generic_update_time() correctly returns -EAGAIN when IOCB_NOWAIT
is set and ->dirty_inode could block, matching the behavior
already adopted by XFS, FUSE, and ext2.
Affected paths:
- ext4_dio_write_checks(): DIO NOWAIT write
- ext4_write_checks(): shared by buffered (rejects NOWAIT upfront)
and DAX write (supports NOWAIT)
ext4_fallocate() in extents.c is not affected as it has no kiocb.
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Link: https://patch.msgid.link/20260629113827.4074335-6-libaokun@linux.alibaba.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
For unaligned DIO writes, the previous ext4_overwrite_io() required the
entire range to fall within a single written extent. This was overly
conservative: the DIO layer only performs partial block zeroing for the
head and tail blocks when they are partially covered by the write.
Middle blocks that are fully covered are written as whole blocks
without any zeroing, so they are safe regardless of extent state.
Therefore exclusive lock is only required when partial block zeroing
will actually happen:
- The head partial block (if any) lands on a hole or unwritten extent.
- The tail partial block (if any) lands on a hole or unwritten extent.
Middle full-cover blocks can be in any state (hole, unwritten, or
written) - block allocation under shared lock is safe per the previous
patch's analysis (inode_dio_begin + i_data_sem protection).
Replace ext4_overwrite_io() with ext4_dio_needs_zeroing(), which
directly answers the question driving the lock decision. It uses at
most two ext4_map_blocks() calls: one for the head partial block (also
catching the case where it spans through the tail), and one for the
tail partial block if not already covered.
This enables shared lock for previously-rejected scenarios such as:
- Unaligned write spanning written extent + mid-range hole + written
extent at the tail.
- Unaligned write where the partial blocks land on written extents but
the middle has unwritten extents.
Performance:
Hardware: /dev/sda (rotational disk, ~1 GB/s sustained write)
Filesystem: ext4 default mkfs
Unaligned DIO writes (14336 bytes at +512 within each 16K stripe).
Each stripe is laid out as [written][unwritten][unwritten][written],
so the head and tail partial blocks land on written extents but the
middle is unwritten. Metric: IOPS.
JOBS Before After speedup
---- -------- --------- -------
1 15,547 17,381 1.12x
2 15,910 34,172 2.15x
4 15,014 57,567 3.83x
8 15,022 81,947 5.46x
16 14,586 99,126 6.80x
32 14,047 92,519 6.59x
Wall time at JOBS=32: 149.3s (Before) -> 22.7s (After), 6.58x faster.
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Link: https://patch.msgid.link/20260629113827.4074335-5-libaokun@linux.alibaba.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Currently, ext4_dio_write_checks() calls ext4_overwrite_io() to
determine if a write is a pure overwrite, and upgrades to exclusive
i_rwsem if not. However, ext4_overwrite_io() uses a single
ext4_map_blocks() call which only returns the first contiguous extent of
the same type. A write spanning multiple pre-allocated extents (e.g.
written + unwritten, or two physically discontiguous written extents)
produces a false negative, forcing an unnecessary exclusive lock upgrade.
After commit 5d87c7fca2c1 ("ext4: avoid starting handle when dio
writing an unwritten extent") and commit 012924f0eeef ("ext4: remove
useless ext4_iomap_overwrite_ops"), ext4_iomap_begin()'s fast path
accepts both EXT4_MAP_MAPPED and EXT4_MAP_UNWRITTEN without starting a
journal transaction. The iomap iteration naturally handles multi-extent
ranges: each call returns the mapping for the current segment, and
unwritten-to-written conversion is deferred to ext4_dio_write_end_io().
This means the common case of mixed written/unwritten extents never
reaches ext4_iomap_alloc() at all.
Even for the less common case where the range contains a hole and
ext4_iomap_alloc() is needed, exclusive i_rwsem is still unnecessary for
aligned non-extending writes:
- truncate/punch_hole are kept out: they require exclusive i_rwsem
(blocked by our shared lock during allocation), and inode_dio_begin()
keeps their inode_dio_wait() blocked until in-flight bios complete.
- i_data_sem write-lock inside ext4_map_blocks() serializes concurrent
extent tree modifications (parallel writers to the same hole).
- The journal handle is per-thread and does not require i_rwsem
exclusion.
- i_disksize and orphan list are not involved in non-extending writes.
Skip the ext4_overwrite_io() check entirely for aligned writes by
initializing overwrite to true and only calling ext4_overwrite_io() for
unaligned writes. Unaligned writes still need the extent state check
because concurrent partial block zeroing in the DIO layer requires
exclusive serialization unless the range is a pure written-extent
overwrite.
Performance:
Hardware: /dev/sda (rotational disk, ~1 GB/s sustained write)
Filesystem: ext4 default mkfs
Aligned 8K DIO writes spanning written+unwritten extent boundaries.
Each thread writes its own 1G region sequentially; the file is rebuilt
between runs so every block is written exactly once. Metric: IOPS.
JOBS Before After speedup
---- -------- --------- -------
1 42,322 43,329 1.02x
2 68,516 70,677 1.03x
4 62,489 97,072 1.55x
8 58,701 110,819 1.89x
16 58,569 116,392 1.99x
32 60,860 117,244 1.93x
Wall time at JOBS=32: 69.2s (Before) -> 35.4s (After), 1.96x faster.
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Link: https://patch.msgid.link/20260629113827.4074335-4-libaokun@linux.alibaba.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
generic/746 started failing intermittently on ext3 (no-extent inodes).
The test triggers 'Page cache invalidation failure on direct I/O'
warnings and subsequent fsync returns -EIO. Adding a 50ms delay
between ext4_buffered_write_iter() and filemap_write_and_wait_range()
in ext4_dio_write_iter() makes the race almost always reproducible.
On no-extent inodes, DIO writes to holes cannot use unwritten extents,
so ext4_iomap_alloc() leaves m_flags=0 and ext4_map_blocks() returns 0.
The iomap layer then returns -ENOTBLK, causing fallback to buffered I/O.
The fallback path in ext4_dio_write_iter() calls
ext4_buffered_write_iter() which dirties pages, then does flush and
invalidate. However, there's an unprotected window between
ext4_buffered_write_iter() returning (with inode lock released) and
the subsequent flush+invalidate.
Concurrent async DIO completions from other threads can run
kiocb_invalidate_post_direct_write() during this window. If pages have
been re-dirtied, post-invalidation finds dirty pages and triggers the
warning, setting -EIO in the error sequence.
Consider a file with two 4k extents: [hole][written]. Thread A does
DIO to the written extent, while thread B does DIO spanning both:
kworker A (4k DIO, allocated block) kworker B (8k DIO, fallback)
----------------------------------- ----------------------------
inode_lock_shared() inode_lock_shared()
iomap_dio_rw(): iomap_dio_rw():
kiocb_invalidate_pages -> clean iomap_begin -> -ENOTBLK
submit_bio (async) dio->size = 0
inode_unlock_shared() inode_unlock_shared()
[bio pending in block layer] /* fallback: lock released */
ext4_buffered_write_iter()
inode_lock(exclusive)
generic_perform_write()
-> dirty pages [0, 8k]
inode_unlock(exclusive)
/* pages dirty, no lock */
[bio completes] filemap_write_and_wait_range()
iomap_dio_complete() -> flush dirty pages
kiocb_invalidate_post_direct_write() invalidate_mapping_pages()
invalidate_inode_pages2_range()
-> finds dirty page!
-> dio_warn_stale_pagecache()
-> errseq_set(-EIO)
This issue can be triggered through normal I/O paths, not just
intentionally overlapping DIO writes from userspace. For example,
generic/746 uses a loop device where multiple kworkers issue concurrent
I/O to the backing file. Additionally, when block_size < folio_size,
non-overlapping DIO writes that share a large folio can also trigger
the race.
Add inode_dio_wait() in ext4_buffered_write_iter() before
ext4_write_checks() to drain all in-flight DIO. This ensures that
all DIO clears existing pages before submitting IO (via
kiocb_invalidate_pages()), all BIO waits for all DIO to complete
(via inode_dio_wait()), and ext4_write_checks() observes the inode
size after all completed DIO so that ext4_block_zero_eof() does not
race with in-flight DIO, thus eliminating the race.
Fixes: 378f32bab371 ("ext4: introduce direct I/O write using iomap infrastructure")
Suggested-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/d1adcf7c-c276-458d-9cac-68a4410f7626@gmail.com
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Link: https://patch.msgid.link/20260629113827.4074335-3-libaokun@linux.alibaba.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Block allocation requires journal access which may sleep, violating
NOWAIT semantics. Return -EAGAIN early when IOMAP_NOWAIT is set,
allowing the caller to retry without the NOWAIT constraint.
This ensures that write paths using IOMAP_NOWAIT (e.g., DIO with
RWF_NOWAIT) will not block on journal operations when blocks need
to be allocated.
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260611163441.2431805-1-libaokun@linux.alibaba.com?part=1
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Link: https://patch.msgid.link/20260629113827.4074335-2-libaokun@linux.alibaba.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
In data=journal mode, the writeback thread can hit the
WARN_ON_ONCE(sb_rdonly(sb)) in ext4_journal_check_start() while the
superblock is being remounted read-only during reboot:
Workqueue: writeback wb_workfn (flush-253:0)
RIP: 0010:ext4_journal_check_start+0x8b/0xd0
Call Trace:
__ext4_journal_start_sb+0x3c/0x1e0
mpage_prepare_extent_to_map+0x4af/0x580
ext4_do_writepages+0x3c0/0x1080
ext4_writepages+0xc8/0x1a0
do_writepages+0xc4/0x180
__writeback_single_inode+0x45/0x2f0
writeback_sb_inodes+0x26b/0x5d0
__writeback_inodes_wb+0x54/0x100
wb_writeback+0x1ac/0x320
wb_workfn+0x394/0x470
And followed by the warning:
EXT4-fs warning (device vda1): ext4_evict_inode:195: inode #6263:
comm (sd-umount): data will be lost
This issue is not reproduced every time, but frequently.
The reproduction step is to create a VM with 8 CPUs, 16G memory and
setup data=journal:
sudo tune2fs -o journal_data /dev/vda1
Run fio:
rm -f fiotest
fio --name=fiotest --rw=randwrite --bs=4k --runtime=6 --ioengine=libaio
--iodepth=256 --numjobs=8 --filename=fiotest --filesize=30G
--group_reporting
Reboot the VM, and check the console output from:
virsh console testvm
But there is no dirty inode, folio_clear_dirty_for_io clears PG_dirty
but leaves tags PAGECACHE_TAG_DIRTY and PAGECACHE_TAG_TOWRITE set which
are only cleared by __folio_start_writeback.
In data=journal mode, jbd2 checkpoints the journalled data to its final
location and clears its own dirty flag without touching folio PG_dirty
or xarray dirty flags.
The commit f4a2b42e7891 ("ext4: fix stale xarray tags after writeback")
fixes when PG_dirty is still set but there is no dirty page.
Another case is PG_dirty is cleared, but PAGECACHE_TAG_DIRTY and
PAGECACHE_TAG_TOWRITE is still set. In this case, writeback thread
checks clean folio and skips it in mpage_prepare_extent_to_map:
if (!folio_test_dirty(folio) ||
...
folio_unlcok(folio);
continue
And never reaches ext4_bio_write_folio where the commit f4a2b42e7891
clears the stale xarray tags. Print debug logs after the filesystem
is remounted read-only:
writepages RDONLY nrpages=2048 dirtytag=1 wbtag=0 towrite=1 sync=0
And all folios are actually clean:
folio idx=3 dirty=0 wb=0 checked=0 dirtybuf=0 jbddirty=0 mapped=1
...
We need to clear the xarray stale tags for such clean folios by
cycling them through writeback in the skip path, the same way
f4a2b42e7891 does in ext4_bio_write_folio.
Fixes: dff4ac75eeee ("ext4: move keep_towrite handling to ext4_bio_write_page()")
Signed-off-by: Gerald Yang <gerald.yang@canonical.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260625160127.162272-1-gerald.yang@canonical.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Syzbot/stress-ng reported an ABBA deadlock in ext4 when exercising
concurrent xattr workloads (using the ea_inode mount/format option).
The deadlock occurs between the running transaction and the eviction
thread:
- Task 1 (stress-ng): Holds a reference to a shared mbcache_entry (ce)
and calls ext4_xattr_inode_cache_find() -> ext4_iget() to retrieve
the corresponding EA inode. Since the EA inode is currently being
evicted, ext4_iget() blocks in __wait_on_freeing_inode() waiting for
eviction to complete.
- Task 2 (eviction thread): Currently evicting the same EA inode in
ext4_evict_ea_inode(). It calls mb_cache_entry_wait_unused(oe) which
blocks waiting for Task 1 to release the reference to the mbcache_entry.
To break this deadlock, implement a new ext4_iget() configuration flag
named EXT4_IGET_NOWAIT. When set, perform a non-blocking lookup of the
inode via VFS's find_inode_nowait() API.
If the inode is currently being evicted (marked with I_FREEING or
I_WILL_FREE) or created (I_CREATING), or if it is not present in the VFS
inode cache (cache miss), simply skip it (returning -ENOENT) rather than
waiting for eviction/creation to complete, breaking the ABBA cycle.
Since we return -ENOENT immediately on a cache miss, we never attempt to
allocate a new inode or call iget_locked(), completely eliminating any
TOCTOU race window.
If the returned inode is I_NEW, wait for its initialization to clear via
wait_on_new_inode(). If initialization fails and the inode is unhashed
during wait_on_new_inode() waking up (e.g., due to an I/O read error in
another thread), safely drop the reference and return -ENOENT. This
unhashed check is executed unconditionally on all cache-hit pathways to
properly handle concurrent initialization failures.
Finally, standard validation checks (including is_bad_inode,
EXT4_EA_INODE_FL, file_acl, and xattr flags) are executed as normal inside
check_igot_inode() to fully guarantee VFS-layer safety.
In ext4_xattr_inode_cache_find(), invoke ext4_iget() with the new
EXT4_IGET_NOWAIT flag to perform the non-blocking cache search.
Suggested-by: Jan Kara <jack@suse.cz>
Reported-by: Colin Ian King <colin.i.king@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219283
Fixes: 0a46ef234756 ("ext4: do not create EA inode under buffer lock")
Signed-off-by: Aditya Prakash Srivastava <aditya.ansh182@gmail.com>
Tested-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260626054821.1729-1-aditya.ansh182@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
ksmbd_decompress_request() bounds the decompressed size only against
the maximum request size. A compression transform can therefore
produce a buffer smaller than an SMB2 PDU and install it as
conn->request_buf.
The receive path subsequently calls ksmbd_smb_request(), which reads
the protocol ID before the normal SMB2 minimum-size check. If the
decompressed output is too short, that read can access beyond the
request allocation.
Require the decompressed output to contain at least a complete minimum
SMB2 PDU before allocating and installing the replacement request
buffer.
Fixes: a08de24c2b85 ("ksmbd: negotiate and decode SMB2 compression")
Cc: stable@vger.kernel.org
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
The receive path applies the minimum SMB2 PDU size check only when
ProtocolId is SMB2_PROTO_NUMBER. A packet carrying
SMB2_TRANSFORM_PROTO_NUM bypasses the check even when the negotiated
dialect does not provide transform handling.
On an SMB 2.1 connection, a short transform packet therefore reaches
init_smb2_rsp_hdr(), which interprets the request as a full SMB2 header
and reads beyond the request allocation. The copied fields can then be
returned to the unauthenticated client.
Compression transforms are converted to ordinary SMB2 messages before
protocol validation. After that conversion, validate ordinary SMB2
requests against SMB2_MIN_SUPPORTED_PDU_SIZE and require encryption
transform requests to contain both a transform header and an SMB2
header. This rejects truncated requests before work allocation.
Fixes: 368ba06881c3 ("ksmbd: check the validation of pdu_size in ksmbd_conn_handler_loop")
Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-31063
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
In ntlm_authenticate(), destroy_previous_session() is called using a
user pointer resolved from the client-supplied NTLM blob username field
before the NTLMv2 response is validated. An authenticated attacker can
set the NTLM blob username to match a victim account and set
PreviousSessionId to the victim's session ID; destroy_previous_session()
destroys the victim's session while ksmbd_decode_ntlmssp_auth_blob()
subsequently rejects the request with -EPERM.
Move destroy_previous_session() and the prev_id assignment to after
ksmbd_decode_ntlmssp_auth_blob() returns success and use sess->user
rather than the pre-authentication lookup result. This matches the
ordering already used by krb5_authenticate(), where
destroy_previous_session() is called only after
ksmbd_krb5_authenticate() returns success.
Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/linux-cifs/20260702155449.3639773-1-james_montgomery@disroot.org/
Signed-off-by: James Montgomery <james_montgomery@disroot.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
set_ntacl_dacl() validates sid.num_subauth before copying an ACE, but
does not verify that the declared ACE size contains all sub-authorities
described by that field. An undersized ACE can therefore be copied
and later make the POSIX ACL deduplication walk inspect data beyond
the copied ACE boundary.
The existing initial bound check is also too small. It only ensures
that the ACE size field is accessible before set_ntacl_dacl() reads
sid.num_subauth farther into the input buffer.
Require enough input for the fixed SID header before accessing
num_subauth, reject ACEs smaller than that header, and skip ACEs
whose declared size cannot contain the complete SID. This makes the
validation consistent with the other ACE walk paths.
Reported-by: LocalHost <localhost.detect@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
check_add_overflow() unconditionally writes the truncated sum into *d
even on overflow, per its contract in include/linux/overflow.h.
The four check_add_overflow() guards in set_posix_acl_entries_dacl()
and set_ntacl_dacl() break out of the ACE-building loops on overflow,
but the truncated *size is then consumed downstream at the end of
set_ntacl_dacl():
pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size);
This produces an on-wire NT ACL whose pndacl->size under-reports the
bytes actually written by the preceding fill_ace_for_sid()/memcpy()
calls, yielding a malformed ACL that can trigger out-of-bounds reads
when re-parsed by clients or ksmbd itself.
Restore *size to its pre-addition value on each overflow branch (via
`*size -= ace_sz` / `size -= nt_ace_size`) so that after the break,
*size once again holds the cumulative size of the successfully-written
ACEs. The committed ACL is then truncated-but-self-consistent rather
than malformed.
The ksmbd DACL builders are the only check_add_overflow() sites found
where an overflow path breaks out of a loop and the destination value
is consumed afterward. The other nearby break-style cases either
return -EINVAL on overflow (transport_ipc.c) or break without
consuming the overflowed destination value afterward (buildid.c).
Fixes: 299f962c0b02 ("ksmbd: use check_add_overflow() to prevent u16 DACL size overflow")
Assisted-by: atomcode:glm-5.2
Assisted-by: Codex:gpt-5.5
Cc: stable@vger.kernel.org
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
set_ntacl_dacl() can stop copying ACEs before consuming the full input
DACL when size accounting overflows.
When that happens, num_aces reflects only the ACEs that were actually
copied into the output DACL, but set_posix_acl_entries_dacl() still
receives nt_num_aces and uses it to walk the existing ACE array during
dedup.
That makes the dedup walk scan past the copied ACE array and inspect
buffer tail that does not contain valid ACEs.
Split the two meanings currently carried by the NT ACE count. Pass the
number of copied NT ACEs to bound the dedup walk, and preserve the
original "input DACL had NT ACEs" state separately for the
Everyone/default ACL fallback.
This keeps the dedup walk aligned with the ACEs that are actually
present in the rebuilt DACL.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
SMB2_FLAGS_SIGNED is controlled by the incoming request and only indicates
that a signature accompanies that request. Do not use it to decide whether a
signing-required session must authenticate the request.
Reject an unsigned plaintext request before dispatch when the session
requires signing. Continue to validate signatures on signed requests,
including when signing is optional. Encrypted requests have already been
authenticated during decryption.
An OPLOCK_BREAK acknowledgment is a session request and is subject to the
same signing rule, so do not exclude it from signed-request detection.
Reported-by: Charles Vosburgh <trilobyte777@gmail.com>
Tested-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
The VFS initializes a child's POSIX ACL from the parent's default ACL and
the requested creation mode. Do not mutate the parent ACL or overwrite the
child's VFS-computed access and default ACLs afterwards.
This preserves restrictive ACL_MASK entries and prevents SMB object creation
from widening effective permissions.
Reported-by: Charles Vosburgh <trilobyte777@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
FS_IOC32_GETVERSION has a distinct compat command encoding. Passing it
through compat_ptr_ioctl() leaves pidfd_ioctl() unable to recognize the
otherwise architecture-independent inode generation query.
Translate the compat command to FS_IOC_GETVERSION before dispatching it
through the native pidfd ioctl implementation.
Signed-off-by: Li Chen <me@linux.beauty>
Link: https://patch.msgid.link/20260716052822.1034228-1-me@linux.beauty
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
Commit 5dae222a5ff0c ("vfs: allow copy_file_range to copy across devices")
allowed filesystems that implement the copy_file_range() f_op to decide
if they want to access cross-sb copy from/to the same fs type.
The same commit added checks to verify same sb copy for filesystems that
implement ->copy_file_range() and do not support cross-sb copy at the
time, namely, to ceph, fuse and nfs.
The two remaining fs which implement ->copy_file_range(), cifs and
overlayfs started to support cross-sb copy from this time.
While overlayfs does support cross-sb copy when the two underlying files
are on the same base fs, the copy operation on the two real files from
two different overalyfs filesystems is performed with the mounter
creds of the destination overlayfs and the read permission access hook
for the source file was called with the wrong creds.
This could cause either deny of access to copy which would otherwise be
allowed (e.g. with splice) or allow read access to file which would
otherwise be denied.
Fix the latter case by explicitly verifying read access to source file
with the source overlayfs mounter creds.
The former case remains a quirk of cross-sb overlayfs copy, but
userspace could fall back to regular copy so no harm done.
Fixes: 5dae222a5ff0c ("vfs: allow copy_file_range to copy across devices")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://patch.msgid.link/20260712122421.203113-1-amir73il@gmail.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
Don't return the return value of down_read_killable() (0) when a ptrace
access check fails, return -EACCES as intended.
Reported-by: Magnus Lindholm <linmag7@gmail.com>
Closes: https://lore.kernel.org/r/20260706170735.2941493-1-linmag7@gmail.com
Fixes: 6650527444da ("proc: protect ptrace_may_access() with exec_update_lock (part 1)")
Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Link: https://patch.msgid.link/20260706-procfs-ns-eacces-fix-v1-1-a69ab14c02e6@google.com
Tested-by: Magnus Lindholm <linmag7@gmail.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
Convert open-coded kmalloc() multiplication to the modern kmalloc_objs()
interface to improve type safety and prevent potential integer
overflows.
No functional changes are intended.
Signed-off-by: Cihan Karadag <cihan.cihan@gmail.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
|
|
Now that there is xfs_metadir_create_file() mark
xfs_metadir_start_create(), xfs_metadir_create() and xfs_metadir_cancel()
as static and remove them from xfs_metadir.h.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
|
|
Now that we have xfs_metadir_create_file() use it in
xfs_rtginode_create().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
|
|
Now that we have xfs_metadir_create_file() use it in
xfs_dqinode_metadir_create().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
|
|
Factor the metadata inode create/commit/cleanup lifecycle out of
xfs_metadir_mkdir into a reusable helper that takes an optional callback
to initialize the new inode, and convert xfs_metadir_mkdir to it.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
|
|
If the underlying block device supports the unmap write zeroes
operation, this flag allows users to quickly preallocate a file with
written extents that contain zeroes. This is beneficial for subsequent
overwrites as it prevents the need for unwritten-to-written extent
conversions, thereby significantly reducing metadata updates and journal
I/O overhead, improving overwrite performance.
Punch the range first so it becomes a hole, update the size via
xfs_falloc_setsize() while it is still a hole (so its xfs_zero_range()
skips it and avoids rezeroing), then convert it to written
zeroed extents. A crash between the size update and the conversion is
safe, as a hole within i_size reads back as zeroes.
Co-developed-by: Lukas Herbolt <lukas@herbolt.com>
Signed-off-by: Lukas Herbolt <lukas@herbolt.com>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
|
|
xfs_alloc_file_space() hardcodes XFS_BMAPI_PREALLOC to preallocate
unwritten extents across a range.
In preparation for FALLOC_FL_WRITE_ZEROES, add an explicit allocation
mode argument, enum xfs_alloc_file_space_mode, and derive the xfs_bmapi
flags from it. The only mode for now is XFS_ALLOC_FILE_SPACE_PREALLOC,
which preallocates unwritten extents and marks the inode as preallocated
exactly as before, so there is no functional change.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
|
